21.A class of mutations that results in multiple contiguous (side-by-side) amino acid changes in proteins is/are probably caused by which the following types of mutations?
(A) recombinant
(B) base analog
(C) transversion
(D) frameshift
(E) transition

17.Which of the following methods can separate proteins based on their mass? (A) SDS polyacrylamide gel electrophoresis (B) Isoelectric focusing electrophoresis (C) Ion exchange chromatography (D) Gel filtration chromatography (E) Centrifugation

複選題18.The fluidity of lipid membrane in cells is influenced by? (A) Temperature (B) The amount of unsaturated fatty acyl chain (C) The length of the fatty acid chain (D) The amount of the cholesterol (E) The nature of the membrane-associated proteins

複選題19. Which of the following statements regarding to cell cycle is/are CORRECT? (A) DNA replication starts from the G1 phase (B) Mitosis occurs in the M phase (C) Degradation of cyclins is important in mitosis (D) DNA damage can cause cell cycle arrest (E) The GO phase is the interval between the termination of DNA replication and the onset of mitosis

20.Which of the following events occurs in prokaryotes but not in eukaryotes? (A)Post-transcriptional splicing (B) Translation in the absence of a ribosome (C) Concurrent transcription and translation (D) Post-translational modification (E) Alanine can be added to polypeptide chain by tRNA with different codon.

複選題22. Which of the following is/are functional elements of a plasmid? (A) centromere (B) drug-resistance gene (C) polylinker sequence (D) origin of replication (E) autonomously replicating sequence

複選題23. Unlike bacterial mRNA, eukaryotic mRNA must undergo______before it may be used for translation. (A) folding mRNA into hairpin loops (B) export to the cytoplasm (C) capping (D) splicing (E) polyadenylation

複選題24.Which of the following is/are included in the universal features of DNA replication? (A) Release of PPi from a nucleoside triphosphate. (B) Synthesis from the 5' end to the 3' end. (C) Base pairing of A to U and G to C. (D) Use of a primer. (E) None of the above.

25. What method can be used to functionally inactivate a gene without altering its sequence? (A) gene knockout. (B) RNA interference. (C) dominant negative mutation. (D) CRISP/cas9. (E) site-directed mutagenesis.

複選題26.Which of the following statements is/are TRUE? (A) Protein synthesis in prokaryotes always starts with a methionine residue. (B) A Shine-Dalgarno Sequence is a sequence of nucleotides in an mRNA that interacts with the small subunit of a ribosome to begin translation. (C) In bacteria, translation of the mRNA begins during the synthesis of the mRNA. (D) A polysome is a polypeptide chain in the process of being formed. (E) The ribosome is actually a ribozyme.

複選題27. Intracellular second messengers include all of the following? (A) Ca2+. (B) diacylglycerol (DAG). (C) cATP. (D) nitric oxide (NO). (E) cGMP